Casting metals



1, D. J. CAMPBELL 2,303,608

CASTING METAL Filed Oct. 27, 1941 4 Sheets-Sheet 1 Enventor (Ittorneg Dec. 1, 1942.

D. J. CAMPBELL 2,303,608

CASTING METAL Filed Oct. 27, 1941 4 Sheets-Sheet'2 Snventor;

-,- Dmza/J JJmy/floall By I u i af forneg Dec. 1, 1942.

D. J. CAMPBELL CASTING METAL Filed OGt. 27. 1941 4 Sheets-Sheet 3 3nventor hall 61% LA 73W (Ittorneg Patented Dec. 1, 1942 UNITED STATES PATENT OFFICE CASTING METALS Donald J. Campbell, Spring Lake, Mich. Application October 27, 1941, SerialNo 416,683

-4 Claims.

My present invention relates to improvements in casting metals, and particularly to casting crank shafts and other elongated ferrous metal bodies; and the objects of improvement are, first, to provide a method whereby elongated castings of ferrous metal such as steel can be produced cheaply and in large quantities without internal flaws; second, to provide a method, including a mold, whereby elongated castings of irregular shape can be produced that are sound and free from internal shrinkage voids; third, to provide a method, including a mold, whereby elongated metal castings of irregular shapes can be produced having a uniform constituent structure; fourth, to provide a method of casting metals,

including a mold, of which the mold is of simple structure; fifth, to provide a method whereby ferrous metal castings of uniform hardness can be produced; sixth, to provide a method, including a mold whereby castings produced thereby will be substantially free from mold parting fins; seventh, to provide a mold whereby the above named objects can be attained.

I attain these named objects by the method hereinafter described, and the mold together with the apparatus illustrated in the accompanying drawings, in which:

Figure 1 is a longitudinal elevation view of a crank shaft for an internal combustion engine as cast and removed from the mold in which it was cast.

Figure 2 is a vertical sectional view of my mold in which to cast a plurality of crank shafts such as is illustrated in Figure 1, the section being taken on a verticalplane extending transversely of and on the parting line XX, of Figures 3 and 4 of the drawings, and between opposed vertically disposed mold members. t

Figure 3 is a top plan view of my moldassembly with the runner box omitted from the top of the mold in order to disclose the joint between the opposed vertically disposed mold sections.

Figure 4 isa transverse sectional view of my mold, as when looking downward from a horizontal plane at line I-I of Figure 2, the view showing the arrangement of the opposed mold sections, the combined runner and feeder cavity, and gates through which the molten metal is delivered to the mold cavities at the said plane.

Figure 5 is a similar view to that of Figure 4,

. the view diflering therefrom only in that it is taken on a horizontal plane at line IVIV of Figure 3.

Figure 6 is a similar view to that of Figures 3 it is taken on a horizontal plane at line V--V of Figure 3.

Figure 7 is a top plan view of the box in which the mold section members are formed from a Figure 8 is a longitudinal elevation view of one I of the mold section members as made in the box shown in Figure '7.

Figure 9 is a cross-sectional view of the mold sectional members taken on line VI VI of Figure 8. I

Referring to the several views of the drawings, similar numerals refer to similar parts or portions of my invention or devices employed in the carrying out of the invention.

Numeral I designates one mold section member of one plurality of four mold sections, and 2 a mold section member of a second plurality of four mold sections, each mold section member having impressed in its respective widest face, one-half of a mold cavity 3-and one-half of the gate passages 4, 5, 6, 'l and 8, and one-eighth of the combined runner and feeder cavity 9 extending to below the lower end of the mold cavities. Each mold section member has a flat side 2' in incline relation to the widest fiat face having the mold cavity impressed therein, whereby, when the opposed mold section members are placed with their widest fiat face in engagement with each other, their mold cavity impressions will be in register, and form a cross-sectional shape resembling a distorted pentagon forming one-fourth of the completed mold, when assem bled as shown in Figures 3 and 4. Numerals l0 designate heavy metal straps surrounding the mold and having wedges ll driven into the space between the strap and the mold sections, whereby the several mold sections are forced in tight engagement. Each strap l0 has reinforcing ribs l2, whereby the strap is prevented from being sprung or distorted by the wedges ll being driven between the strap and the moldsection. Each mold section member has depressions or recesses and .4, the view differing therefrom only in that I3 into which is set a metal plug-like dowel It at the time the mold section members are assembled. These plug-like dowels retain the mold section members and the cavities therein in accurate registration, Numeral l5 designates the pouring box at the top of the mold for receiving the molten metal from the foundry ladle from which the molten metal passes through skim gate Hi to the combined runner and feeder cavity 9,

and therefrom to the mold cavity through the gate passages 4, I, 3, 'l and]. Numeral l'l represents the supporting plate or platform for supporting the mold in its assembled form.

Referring to Figure 1, numeral It represents a crank shaft as cast in and removed from a mold of my improved structure, and having at one end thereof, feeder head I! from which molten metal is fed to the solidifying metal within the mold cavityfrom the feeder head cavity 20. Numeral 2| represents the box having therein a one-half pattern portion 23 in which I make the mold section members of one order,

the reverse order mold members being made in a like box having an opposite incline angle memwhen the sand forming the mold section member is blown and thereby packed into the box. It is understood that the sand can be packed in the box in any suitable manner, including manually ramming therein against the pattern and the surplus sand extending above the box, struck oil. In removing the moldsection member from the box 2|, I place a drier plate over the top of the box and turn the box over so that the plate is.

under the section and then withdraw the box from the mold section member, leaving the incline angle member portion 25 to support the overhang of the mold section member during the drying stage of the member. Or, I provide a plate having an upward incline portion corresponding to the incline angle of the side 2 of the mold section member, and remove the box from the mold section member supported by the upwardly inclined portion of the plate having the upward incline portion extending the length of the mold member.

Referring to Figure '7 of the drawings, in which is illustrated the box 2| wherein are made mold members 2, there being a similar box in which to make mold members I, each of the said boxes has therein secured on the bottom of the box, pattern member 23, which is one transverse half of the complete pattern, in the present instant, that of an internal combustion engine crank shaft having six throws, the pattern having portion 26 whereby is formed feeder cavity 20 of Figure 8, runner gate forming members 21, 28, 29, and 3|). The runner gate forming members 21 and 29 form runner gates extending between the combined runner and feeder cavity 9 formed by the one-fourth cylindrical member 33 extending at acute angle corner of the box 2| and crank cheek portions 3|, which are heavier than the cheek portions 32 separating the several bearing and crank portions of the shaft, and the runner gate. Also fastened to the topside of the bottom of the box 2| are bosses 34, that form depressions l3 in the widest flat side of the mold members 2 or 3, and at theright angle corner of the box 2| at the cheeks 3| and 32 are prints 35 forming a pocket in the widest side of the mold member wherein can be set a core member for forming the underside of an overhang of the said cheek members.

In practicing my improved method of casting metals, I provide a box as described in which to make or to form one of the mold section members I, having impressed into its widest flat face a portion of a moldcavity, a portion of a runner gate and of a combined runner and feeder cavity, and a fiat side in incline relation to the said widest fiat face. Havingprovided the said box, I provide another like box of a reverse order to that of the first named box. In these two boxes,

I pack, as by blowing from a hopper, throwing by an impeller. or manual ramming, mold material such as moistened sand having mixed therewith a suitable binder. Having provided a suitable drier plate for supporting the mold section member, that may or may not have an upwardly inclined portion corresponding to the incline fiat portion 23 of the mold section member, and having filled and packed the core material within the box, I place the drier plate on the open side of the box, turn over the box together with the undried mold section member therein, so that the drier plate will be in supporting position for the mold section member, which at that stage will be undried. Having removed the box from the mold section member, I place the said drier and mold section in a suitable oven and bake the section until it has been thoroughly dried. After a mold section of each order is dried, I [place the metal plug-like dowel I in the recesses ii of one of the mold sections, apply a paste on the surface of the mold section member, and place the mold section member of the other order against the first named mold section member with the mold cavities in register. Having provided four of these combined mold section, sections, I stand these combined section, sections on a suitable support with a paste applied to the incline surfaces of each section member, then apply the metal binding straps III in spaced apart relation to each other, as shown, around the assembled mold section members, and drive wedges between the mold sections and the metal straps, thereby forcibly positioning the several mold sections in adjusted engaged relation. When the mold sections have been assembled asdescribed, I mount a pouring box on the top of the mold, which completes the mold and places it in readiness for receiving the molten metal, which usually consists of an alloy steel having a temperature in excess of 2800 degrees Fahrenheit, which is poured from the foundry ladle into the runner box from where it passes through the skim gate I6 into the combined runner and feeder cavity, therefrom through gate passages l, 5, 8, I and 8 into the mold cavities to therein be formed into the casting, the mold cavity is rovided for.

When the molten metal has been delivered to the mold cavity, it immediately starts to cool and solidify, first at the contracting surface of the mold cavity and thereafter gradually diminishing in temperature toward the central axis of the mold cavity until the whole casting has solidified with considerable shrinking of the casting, of which the exterior cooling and solidifying takes place first. Unless provision is made to feed molten metal to the central portion of the casting which is still in a molten state, there will develop voids consisting of ragged cavities adjacent the heavier sections of the casting, or the outer shell of solidified metal may be drawn in and thereby cause depressions at the outer surface of the casting. In order to overcome these named defects, the mold cavities have at their top, feeder head cavities 20 from which molten metal is drawn during solidification and shrinkage of the casting in the mold cavity.

To further overcome voids and depressions, I

have the gate passages 4, 5, 6, I and 8 of considerable cross-sectional area and of short lengths between the mold cavity and the combined runner and feeder cavity from which molten metal is also drawn by shrinkage of the casting within the mold cavity or cavities. Figure 1 illustrates the feeder head IQ of the crank shaft l8 as formed by the feeder cavity 20 of my improved mold.

Having described my present invention, the rights which I desire to secure are set forth in the claims hereafter enumerated; and I claim:

1. In the herein described method of castin metals, a mold comprising a plurality of {our distorted pentagon transversely shaped mold sections, each having therein a cavity in which to cast a crank shaft, the said mold cavity comprismg a plurality of bearing casting portions, a plurality of crank cheek casting portions of light and heavy weight, an end bearing casting portion, a feeder head casting, one-fourth of a combined runner and feeder cavity extending longitudinally of and substantially parallel with the cavity in which to cast the crank shaft, a runner gate extending from the combined runner and feeder cavityto the feeder head casting portion,

a runner gate extending from the combined runner and feeder cavity to one of the heavy crank cheek casting portions, a runner gate extending from the combined runner and feeder cavity to one of the crank pin casting portions, a second runner gate extending from the combined runner and feeder cavity to another heavy crank cheek casting portion, a runner gate extending from the combined runner and feeder cavity to the end bearing casting portion. I

2. In the herein described method of casting metals, a mold comprising a plurality of four distorted pentagon, cross-sectional shaped. verticalhead cavity at the upper portion of the moldcavity and having connection therewith.

3. In the herein described method of casting metals, a mold comprising a plurality of four distorted pentagon, cross-sectional shaped, vertically disposed sections in bonded vertical relation with each other, each section having therein a. mold cavity in which to cast a metal body including a feeder head, one-fourth of a combined runner and feeder cavity extending downward from the top of section, a plurality of gate passages extending from the said one-fourth of the combined runner and feeder cavity to the mold cavity for delivering molten metal to the mold cavity in spaced apart relation intermediate the ends of the mold cavity.

4. In the herein described method of casting metals, a mold comprising a plurality of a plurality of half distorted, pentagon-like cross-sectional shaped members of reverse order in bonded vertical relation with each other, each of said members having a side in engagement with a side of an adjacent member and having a portion of a. mold cavity, a portion of a gate passage and a portion of a combined runner and feeder cavity impressed in the widest side in engagement with the widest side of the adjacent member, and a plurality of dowel members extending into each of said mold members at the widest side thereof.

DONALD J. CAMPBELL. 

